to prevent them from gaining a nuclear weapon. if he lets it go, the threat in iran is weakened. >> john, and the question that experts kept raising with me today, over and over again, is why. why would asaad use chemical weapons now, especially when the president has repeated that this is a red line that cannot be crossed? >> in washington, d.c., tonight paul, thank you and as we mentioned the big news from europe tonight, british lawmakers said no to military intervention, and are backing the u.s. if the white house decides to strike. simon mcgregor has more from london. order. >> to the speaker of the british house of commons. bad news for david cameron and his coalition. >> the ayes to the right. the no's to the left, 285. >> his motion asking for support the the principle note reaction, defeated by 13 votes.